Reciprocating linear actuators have been used as a drive source for a reciprocatory electric shaver (see, for example, Japanese laid-open patent publication No. HEI 7-313746). Such a reciprocating linear actuator (reciprocating motor) includes a stator and a plurality of movable elements that perform a reciprocating motion relative to the stator. The plurality of movable elements are associated with respective movable cutters of a plurality of cutter heads and configured to be driven by the single stator. Disposed between the plurality of movable elements is a connection body formed of a coiled spring. When reciprocating displacement amount of one of the movable elements is going to abruptly decrease due to a heavy load applied thereto, the connection body allows the decrease to be stopped by the other movable element, thus preventing a decrease in reciprocating displacement amount of only one of the movable elements so as to provide a well-balanced uniform amplitude.
However, the construction in which the connection body formed of the coiled spring is disposed between the movable elements requires a considerable space, thus making it difficult to reduce the size of the reciprocating linear actuator.
In another linear actuator, movable elements are connected by a connection body that is a flat spring displaceable in the reciprocating direction of the movable elements (see, for example, Japanese laid-open patent publication No. HEI 11-136921). This construction can require less space for the connection body as compared to that using the connection body formed of the coiled spring. However, the connection body formed of the flat spring disclosed therein has an E-shaped configuration in which one end of each of three flat spring pieces substantially parallel to each other is connected to the movable element while the other ends are linked together. Therefore, the spring characteristic of the portion for linking the plurality of flat spring pieces is inferior to that of the flat spring pieces. On the whole, the portion of the connection body that has an effective spring characteristic is short as compared to the overall length (size) thereof. Thus, for a desired spring characteristic, a large flat spring is required on the whole, so that it is difficult to reduce the size.
The present invention has been developed in view of the above mentioned problems, and it is an object of the present invention to provide a reciprocating linear actuator in which a resilient connection body requiring relatively less space for installation is employed for connecting movable elements so as to be advantageous to reduction in size of the actuator.